Research On Measurement Method Of Acoustic Parameters Of Transducer Based On Ultra-short Baseline Positioning

Directivity and sound source level are extremely important acoustic parameters of the transducer.With the decrease of the working frequency of the transducer,the size of the transducer becomes larger and larger,it is more and more difficult to measure the directivity and the sound source level of the transducer by the existing measurement methods,and the performance of transducer will change before and after the installation of the real ship,which also puts forward the demand for the detection of transducer on the real ship.Therefore,this paper proposes a method of measuring acoustic parameters of transducer based on ultra-short baseline positioning,and establishes a set of measurement system,and a set of measurement system is established to measure the directivity and sound source level of low frequency transducer below 5 k Hz.This paper first analyzes the limitations of the existing transducer measurement methods in the measurement of low-frequency and large-scale transducers,and then studies the directivity of transducers and the significance and measurement principle of sound source level,on this basis,a method of acoustic parameter measurement of transducer based on ultra-short baseline positioning is proposed.The positioning principle and the coordinate conversion principle of the ultra-short baseline applied in the measurement method are studied,and the positioning accuracy of the ultra-short baseline is improved from the array structure and the phase extraction algorithm.Then,according to the measurement method proposed in this paper,a set of measurement system is designed,including acoustic emission system and acoustic receiving system.The synchronization of transmitting and receiving is realized by GPS second pulse module.Finally,in the laboratory anechoic pool,the sensitivity and phase consistency of the hydrophone are measured for the measurement of sound source level and the improvement of the measurement and positioning accuracy of the lake test,and the sound source level of the positioning transducer is measured for the determination of the appropriate receiving and transmitting distance of the lake test.This method and standard measurement method are used in the lake test field for test,and the test results are compared and analyzed,the-3 d B beam width error of the directivity result is within 7.4%,and the error of the sound source level is within 2%.The measurement error meets the requirement of 10% of the underwater acoustic measurement error,which proves the feasibility of the measurement method and the effectiveness of the developed system.